In certain circuits such as monolithic integrated circuits a possible lack of symmetry in switching wavefronts can be observed.
This may be related to various factors such as:                statistical mismatch between different silicon wafers due to the production process, which may cause a certain electronic component to behave differently from others;        intrinsic design and/or simulation errors due to the non-ideal behavior of circuit layouts and the models of elementary components;        architectural lack of symmetry due, for example, to differential input offsets, mirror errors, non-zero output resistance values of voltage generators, complexity in the architectures adopted for implementing a high-voltage components;        lack of symmetry due to temperature variations which affect circuit behavior due to changes in electrical conductivity of the components;        variations in reference and/or supply voltages which may change the bias conditions of components and node dynamics as well, by affecting gain and speed; and/or        variations in the electrical parameters of the elementary components due to continued absorption of ionizing radiation (T.I.D.).        